diff --git a/packages/builder/src/components/automation/SetupPanel/CronBuilder.svelte b/packages/builder/src/components/automation/SetupPanel/CronBuilder.svelte
index ee9eed51e9..c731b0afb0 100644
--- a/packages/builder/src/components/automation/SetupPanel/CronBuilder.svelte
+++ b/packages/builder/src/components/automation/SetupPanel/CronBuilder.svelte
@@ -2,15 +2,34 @@
   import { Button, Select, Input, Label } from "@budibase/bbui"
   import { onMount, createEventDispatcher } from "svelte"
   import { flags } from "stores/backend"
+  import { helpers, REBOOT_CRON } from "@budibase/shared-core"
 
   const dispatch = createEventDispatcher()
 
   export let value
+  let error
+
+  $: {
+    const exists = CRON_EXPRESSIONS.some(cron => cron.value === value)
+    const customIndex = CRON_EXPRESSIONS.findIndex(
+      cron => cron.label === "Custom"
+    )
+
+    if (!exists && customIndex === -1) {
+      CRON_EXPRESSIONS[0] = { label: "Custom", value: value }
+    } else if (exists && customIndex !== -1) {
+      CRON_EXPRESSIONS.splice(customIndex, 1)
+    }
+  }
 
   const onChange = e => {
-    if (e.detail === value) {
+    if (value !== REBOOT_CRON) {
+      error = helpers.cron.validate(e.detail).err
+    }
+    if (e.detail === value || error) {
       return
     }
+
     value = e.detail
     dispatch("change", e.detail)
   }
@@ -41,7 +60,7 @@
     if (!$flags.cloud) {
       CRON_EXPRESSIONS.push({
         label: "Every Budibase Reboot",
-        value: "@reboot",
+        value: REBOOT_CRON,
       })
     }
   })
@@ -49,6 +68,7 @@
 
 <div class="block-field">
   <Input
+    {error}
     on:change={onChange}
     {value}
     on:blur={() => (touched = true)}
@@ -64,7 +84,7 @@
     {#if presets}
       <Select
         on:change={onChange}
-        {value}
+        value={value || "Custom"}
         secondary
         extraThin
         label="Presets"
diff --git a/packages/builder/src/components/deploy/AppActions.svelte b/packages/builder/src/components/deploy/AppActions.svelte
index 7d14fd0e87..30f86a79d1 100644
--- a/packages/builder/src/components/deploy/AppActions.svelte
+++ b/packages/builder/src/components/deploy/AppActions.svelte
@@ -101,7 +101,13 @@
     } catch (error) {
       console.error(error)
       analytics.captureException(error)
-      notifications.error("Error publishing app")
+      const baseMsg = "Error publishing app"
+      const message = error.message
+      if (message) {
+        notifications.error(`${baseMsg} - ${message}`)
+      } else {
+        notifications.error(baseMsg)
+      }
     }
     publishing = false
   }
diff --git a/packages/server/src/automations/utils.ts b/packages/server/src/automations/utils.ts
index 0c28787f67..360802df6a 100644
--- a/packages/server/src/automations/utils.ts
+++ b/packages/server/src/automations/utils.ts
@@ -16,9 +16,9 @@ import {
 } from "@budibase/types"
 import sdk from "../sdk"
 import { automationsEnabled } from "../features"
+import { helpers, REBOOT_CRON } from "@budibase/shared-core"
 import tracer from "dd-trace"
 
-const REBOOT_CRON = "@reboot"
 const WH_STEP_ID = definitions.WEBHOOK.stepId
 const CRON_STEP_ID = definitions.CRON.stepId
 let Runner: Thread
@@ -198,6 +198,13 @@ export async function enableCronTrigger(appId: any, automation: Automation) {
     !isRebootTrigger(automation) &&
     trigger?.inputs.cron
   ) {
+    const cronExp = trigger.inputs.cron
+    const validation = helpers.cron.validate(cronExp)
+    if (!validation.valid) {
+      throw new Error(
+        `Invalid automation CRON "${cronExp}" - ${validation.err.join(", ")}`
+      )
+    }
     // make a job id rather than letting Bull decide, makes it easier to handle on way out
     const jobId = `${appId}_cron_${newid()}`
     const job: any = await automationQueue.add(
@@ -205,7 +212,7 @@ export async function enableCronTrigger(appId: any, automation: Automation) {
         automation,
         event: { appId, timestamp: Date.now() },
       },
-      { repeat: { cron: trigger.inputs.cron }, jobId }
+      { repeat: { cron: cronExp }, jobId }
     )
     // Assign cron job ID from bull so we can remove it later if the cron trigger is removed
     trigger.cronJobId = job.id
diff --git a/packages/shared-core/package.json b/packages/shared-core/package.json
index edbbd1dc56..777896a7f7 100644
--- a/packages/shared-core/package.json
+++ b/packages/shared-core/package.json
@@ -14,7 +14,8 @@
     "check:types": "tsc -p tsconfig.json --noEmit --paths null"
   },
   "dependencies": {
-    "@budibase/types": "0.0.0"
+    "@budibase/types": "0.0.0",
+    "cron-validate": "1.4.5"
   },
   "devDependencies": {
     "rimraf": "3.0.2",
diff --git a/packages/shared-core/src/constants/index.ts b/packages/shared-core/src/constants/index.ts
index a23913dd11..99fb5c2a73 100644
--- a/packages/shared-core/src/constants/index.ts
+++ b/packages/shared-core/src/constants/index.ts
@@ -99,6 +99,8 @@ export const SocketSessionTTL = 60
 export const ValidQueryNameRegex = /^[^()]*$/
 export const ValidColumnNameRegex = /^[_a-zA-Z0-9\s]*$/g
 
+export const REBOOT_CRON = "@reboot"
+
 export const InvalidFileExtensions = [
   "7z",
   "action",
diff --git a/packages/shared-core/src/helpers/cron.ts b/packages/shared-core/src/helpers/cron.ts
new file mode 100644
index 0000000000..ca1f1badb7
--- /dev/null
+++ b/packages/shared-core/src/helpers/cron.ts
@@ -0,0 +1,47 @@
+import cronValidate from "cron-validate"
+
+const INPUT_CRON_START = "(Input cron: "
+const ERROR_SWAPS = {
+  "smaller than lower limit": "less than",
+  "bigger than upper limit": "greater than",
+  daysOfMonth: "'days of the month'",
+  daysOfWeek: "'days of the week'",
+  years: "'years'",
+  months: "'months'",
+  hours: "'hours'",
+  minutes: "'minutes'",
+  seconds: "'seconds'",
+}
+
+function improveErrors(errors: string[]): string[] {
+  const finalErrors: string[] = []
+
+  for (let error of errors) {
+    if (error.includes(INPUT_CRON_START)) {
+      error = error.split(INPUT_CRON_START)[0].trim()
+    }
+    for (let [oldErr, newErr] of Object.entries(ERROR_SWAPS)) {
+      if (error.includes(oldErr)) {
+        error = error.replace(new RegExp(oldErr, "g"), newErr)
+      }
+    }
+    finalErrors.push(error)
+  }
+  return finalErrors
+}
+
+export function validate(
+  cronExpression: string
+): { valid: false; err: string[] } | { valid: true } {
+  const result = cronValidate(cronExpression, {
+    preset: "npm-node-cron",
+    override: {
+      useSeconds: false,
+    },
+  })
+  if (!result.isValid()) {
+    return { valid: false, err: improveErrors(result.getError()) }
+  } else {
+    return { valid: true }
+  }
+}
diff --git a/packages/shared-core/src/helpers/index.ts b/packages/shared-core/src/helpers/index.ts
index fd185aa1e9..e76022b14b 100644
--- a/packages/shared-core/src/helpers/index.ts
+++ b/packages/shared-core/src/helpers/index.ts
@@ -1,2 +1,3 @@
 export * from "./helpers"
 export * from "./integrations"
+export * as cron from "./cron"
diff --git a/packages/shared-core/src/tests/cron.test.ts b/packages/shared-core/src/tests/cron.test.ts
new file mode 100644
index 0000000000..d56165b2b8
--- /dev/null
+++ b/packages/shared-core/src/tests/cron.test.ts
@@ -0,0 +1,22 @@
+import { expect, describe, it } from "vitest"
+import { cron } from "../helpers"
+
+describe("check valid and invalid crons", () => {
+  it("invalid - 0 0 0 11 *", () => {
+    expect(cron.validate("0 0 0 11 *")).toStrictEqual({
+      valid: false,
+      err: [expect.stringContaining("less than '1'")],
+    })
+  })
+
+  it("invalid - 5 4 32 1 1", () => {
+    expect(cron.validate("5 4 32 1 1")).toStrictEqual({
+      valid: false,
+      err: [expect.stringContaining("greater than '31'")],
+    })
+  })
+
+  it("valid - * * * * *", () => {
+    expect(cron.validate("* * * * *")).toStrictEqual({ valid: true })
+  })
+})
diff --git a/yarn.lock b/yarn.lock
index 9e12ecad89..fb2f777748 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1980,6 +1980,13 @@
   resolved "https://registry.yarnpkg.com/@babel/regjsgen/-/regjsgen-0.8.0.tgz#f0ba69b075e1f05fb2825b7fad991e7adbb18310"
   integrity sha512-x/rqGMdzj+fWZvCOYForTghzbtqPDZ5gPwaoNGHdgDfF2QA/XZbCBp4Moo5scrkAMPhB7z26XM/AaHuIJdgauA==
 
+"@babel/runtime@^7.10.5":
+  version "7.23.9"
+  resolved "https://registry.yarnpkg.com/@babel/runtime/-/runtime-7.23.9.tgz#47791a15e4603bb5f905bc0753801cf21d6345f7"
+  integrity sha512-0CX6F+BI2s9dkUqr08KFrAIZgNFj75rdBU/DjCyYLIaV/quFjkk6T+EJ2LkZHyZTbEV4L5p97mNkUsHl2wLFAw==
+  dependencies:
+    regenerator-runtime "^0.14.0"
+
 "@babel/runtime@^7.12.5", "@babel/runtime@^7.13.10", "@babel/runtime@^7.15.4", "@babel/runtime@^7.21.0", "@babel/runtime@^7.8.4", "@babel/runtime@^7.9.2":
   version "7.23.8"
   resolved "https://registry.yarnpkg.com/@babel/runtime/-/runtime-7.23.8.tgz#8ee6fe1ac47add7122902f257b8ddf55c898f650"
@@ -5431,6 +5438,11 @@
   resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.200.tgz#435b6035c7eba9cdf1e039af8212c9e9281e7149"
   integrity sha512-YI/M/4HRImtNf3pJgbF+W6FrXovqj+T+/HpENLTooK9PnkacBsDpeP3IpHab40CClUfhNmdM2WTNP2sa2dni5Q==
 
+"@types/lodash@^4.14.165":
+  version "4.14.202"
+  resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.202.tgz#f09dbd2fb082d507178b2f2a5c7e74bd72ff98f8"
+  integrity sha512-OvlIYQK9tNneDlS0VN54LLd5uiPCBOp7gS5Z0f1mjoJYBrtStzgmJBxONW3U6OZqdtNzZPmn9BS/7WI7BFFcFQ==
+
 "@types/long@^4.0.0":
   version "4.0.2"
   resolved "https://registry.yarnpkg.com/@types/long/-/long-4.0.2.tgz#b74129719fc8d11c01868010082d483b7545591a"
@@ -8541,6 +8553,13 @@ cron-parser@^4.2.1:
   dependencies:
     luxon "^3.2.1"
 
+cron-validate@1.4.5:
+  version "1.4.5"
+  resolved "https://registry.yarnpkg.com/cron-validate/-/cron-validate-1.4.5.tgz#eceb221f7558e6302e5f84c7b3a454fdf4d064c3"
+  integrity sha512-nKlOJEnYKudMn/aNyNH8xxWczlfpaazfWV32Pcx/2St51r2bxWbGhZD7uwzMcRhunA/ZNL+Htm/i0792Z59UMQ==
+  dependencies:
+    yup "0.32.9"
+
 cross-spawn@^6.0.0:
   version "6.0.5"
   resolved "https://registry.yarnpkg.com/cross-spawn/-/cross-spawn-6.0.5.tgz#4a5ec7c64dfae22c3a14124dbacdee846d80cbc4"
@@ -14440,7 +14459,7 @@ lock@^1.1.0:
   resolved "https://registry.yarnpkg.com/lock/-/lock-1.1.0.tgz#53157499d1653b136ca66451071fca615703fa55"
   integrity sha512-NZQIJJL5Rb9lMJ0Yl1JoVr9GSdo4HTPsUEWsSFzB8dE8DSoiLCVavWZPi7Rnlv/o73u6I24S/XYc/NmG4l8EKA==
 
-lodash-es@^4.17.21:
+lodash-es@^4.17.15, lodash-es@^4.17.21:
   version "4.17.21"
   resolved "https://registry.yarnpkg.com/lodash-es/-/lodash-es-4.17.21.tgz#43e626c46e6591b7750beb2b50117390c609e3ee"
   integrity sha512-mKnC+QJ9pWVzv+C4/U3rRsHapFfHvQFoFB92e52xeyGMcX6/OlIl78je1u8vePzYZSkkogMPJ2yjxxsb89cxyw==
@@ -14590,7 +14609,7 @@ lodash.xor@^4.5.0:
   resolved "https://registry.yarnpkg.com/lodash.xor/-/lodash.xor-4.5.0.tgz#4d48ed7e98095b0632582ba714d3ff8ae8fb1db6"
   integrity sha512-sVN2zimthq7aZ5sPGXnSz32rZPuqcparVW50chJQe+mzTYV+IsxSsl/2gnkWWE2Of7K3myBQBqtLKOUEHJKRsQ==
 
-lodash@4.17.21, lodash@^4.17.11, lodash@^4.17.14, lodash@^4.17.15, lodash@^4.17.19, lodash@^4.17.21, lodash@^4.17.3, lodash@^4.7.0:
+lodash@4.17.21, lodash@^4.17.11, lodash@^4.17.14, lodash@^4.17.15, lodash@^4.17.19, lodash@^4.17.20, lodash@^4.17.21, lodash@^4.17.3, lodash@^4.7.0:
   version "4.17.21"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
   integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
@@ -22020,6 +22039,19 @@ yocto-queue@^1.0.0:
   resolved "https://registry.yarnpkg.com/yocto-queue/-/yocto-queue-1.0.0.tgz#7f816433fb2cbc511ec8bf7d263c3b58a1a3c251"
   integrity sha512-9bnSc/HEW2uRy67wc+T8UwauLuPJVn28jb+GtJY16iiKWyvmYJRXVT4UamsAEGQfPohgr2q4Tq0sQbQlxTfi1g==
 
+yup@0.32.9:
+  version "0.32.9"
+  resolved "https://registry.yarnpkg.com/yup/-/yup-0.32.9.tgz#9367bec6b1b0e39211ecbca598702e106019d872"
+  integrity sha512-Ci1qN+i2H0XpY7syDQ0k5zKQ/DoxO0LzPg8PAR/X4Mpj6DqaeCoIYEEjDJwhArh3Fa7GWbQQVDZKeXYlSH4JMg==
+  dependencies:
+    "@babel/runtime" "^7.10.5"
+    "@types/lodash" "^4.14.165"
+    lodash "^4.17.20"
+    lodash-es "^4.17.15"
+    nanoclone "^0.2.1"
+    property-expr "^2.0.4"
+    toposort "^2.0.2"
+
 yup@^0.32.11:
   version "0.32.11"
   resolved "https://registry.yarnpkg.com/yup/-/yup-0.32.11.tgz#d67fb83eefa4698607982e63f7ca4c5ed3cf18c5"